Astronaut Mark Kelly and his twin brother Scott have enlisted themselves for a NASA study that will help the space agency gauge the effects of spaceflight on the human body.
Craig Kundrot, deputy chief scientist of NASA's Human Research Programme, says in a news release that the brothers provide a unique opportunity to study two people with the same genetics who were in different environments, the Huffington Post reported.
According to officials, Scott has spent a year in space while Mark was on Earth. NASA said that they are hoping that the studies could be the basis for future research initiatives.
Mark is the husband of former US Rep Gabrielle Giffords, who is recovering after being shot in the head in 2011 in her home district of Tucson.